If you don't know how much money enters and leaves your bank account each month, you're setting yourself up for disaster, in the form of overdrafts, overspending, and debt.

It's simple math: If you're spending more than you earn, you're going to be in debt. And if you don't even have the numbers to plug into that equation, you could be in for a nasty surprise.

You don't have to know down to the cent (we believe you can give yourself $.50 of wiggle room), but you should be able to be more specific than "I earn $90,000 a year, my mortgage is $2,000 a month, and I probably spend a few hundred bucks on food."

"Probably" isn't going to cut it.

How to improve: Start keeping a record of your income and expenses. You can use an app like Mint, LearnVest, or You Need a Budget, an Excel spreadsheet, or even a pen and paper, if that's your style. Knowing how much money it takes to sustain your lifestyle is key.

Once you know how much you earn and how much you spend, some simple arithmetic will reveal how much you can afford to save, invest, or spend on high-tech headphones.

You're carrying credit card debt.

Good debts come from investing in your future, such as buying a house or taking out loans for a college degree. Bad debts, along with typically high interest rates, don't help you build wealth or assets.

Just meeting your obligations each month is also known as "living paycheck to paycheck," and it isn't a sustainable strategy. If you have just enough to pay your bills, what will you do if there's an emergency cost like a hospital bill or car repair? How will you save for grad school, or take a guilt-free weekend away to decompress?

We all know this, on some level: A 2015 survey from GOBankingRates.com found that 20% of Americans fear living paycheck to paycheck.

The GOBankingRates.com survey also found that along with living paycheck to paycheck, Americans' biggest financial fears are living in debt forever and never being able to retire.

How to improve: If you're stressed about money, you know on some level that something isn't right — so it's up to you to take action.

Pinpoint what exactly it is that stresses you out (You don't have enough to cover your bills? You haven't been able to afford something 'just for fun' in months? You're worried you'll have to work forever because you don't have retirement savings?) and take one action to counteract that fear. Putting an extra 1% into savings for the rest of the year might not completely alleviate your stress, but it's better than doing nothing at all.

You've decided to deal with saving for retirement a few years from now.

A 2015 study from Bankrate.com found that only 19% of Americans have increased their savings since last year, and 10% of Americans haven't contributed to their savings at all. According to a 2015 global report issued by HSBC, 38% of working-age people haven't begun to save for retirement, and don't intend to.

That same HSBC report found that 36% of retirees wish they had started saving earlier, and 38% think it's prudent to start planning by age 30.

How to improve: Saving for retirement can take a few different forms — a company-sponsored 401(k) or an IRA are two of the most popular savings vehicles — but no matter how you choose to save, the best thing you can do is start early.

Even if you haven't started putting money away, consider what you want your retirement lifestyle to be like (Travel? Move nearer your family? Downsize your house? Take a part-time job to keep busy?).

You have no idea what your credit score does, much less where it is.

Your credit score, a three-digit number based on the activity detailed in your credit report, is an indicator of your trustworthiness, and helps lenders decide whether they feel comfortable lending you money — which can make all the difference when it comes time to buy something major, like a car or home.

It's easy to let it fall by the wayside.

A survey from Bankrate.com found that less than half of Americans have checked their credit score in the last year (26% have never checked at all), and 35% have never checked their credit reports. By being unaware of their credit, they're setting themselves up for a potentially upsetting — and expensive — surprise the next time they apply for a loan.

How to improve: Sites like CreditKarma, CreditSesame, and Credit.com will give you your score — or at least a very close approximation — for free. You can check your free credit report from each of the three credit bureaus once a year from AnnualCreditReport.com.

By checking regularly, you'll be aware of and able to dispute any mistakes (which are surprisingly common) and prepared to take out a loan when the time comes.

According to that study, more than 40% can't accurately say how much their partner earns, and there are disconnects on how much couples have in investable assets, how they expect to live in retirement, and how they're planning for retirement at all.

If you don't know what your partner earns, spends, and values about money, you don't have the full picture of your household's financials. Communicating ineffectively about money (or refusing to communicate at all) could lead to tension, overspending, debt, and, in the case of at least one person, wrecking your credit score.

... or children.

A 2015 survey from Bank of America and Khan Academy found that 51% of millennials — a young adult generation relatively close to their childhood – say their parents had the greatest impact on how they handle their money, and 78% think that parents should start speaking to kids about money before their teen years.

A 2015 survey from T. Rowe Price found that kids whose parents speak to them about money are more likely to feel that they understand the value of a dollar, and feel they are smart about money.

You're terrified by the idea of investing.

Investing can feel overwhelming, and it's easy to get scared into paralysis by daily market reports and fund options and seemingly limitless jargon.

The good news is, though, that investing your money has the potential for growth far beyond what you'd see in a traditional savings account, and to do it successfully, you don't have to be a pro who cherry-picks "winning" stocks and starts every morning buying and selling various holdings. An analysis by investing app Openfolio found that once you make some investments, the most successful investors actually leave their money alone.

In fact, if you're saving money in a retirement account, or in a 529 account for your child's college, you're investing already. Great start!

You feel like you have something to hide.

You don't have to offer your compensation details to the friend-of-a-friend sitting next to you in a bar, but if you're terrified someone will find out "the truth" about your finances, something clearly isn't right.

That truth doesn't have to be anything nefarious or illegal. It could be that you can't actually afford the luxury car you leased, or that you're barely living paycheck to paycheck, or that you don't have savings, or that your home is too expensive for you to maintain. If you're worried that someone — even your bank manager or credit card company — will find out, there's something worrisome afoot.

You think learning about money is invariably boring.

If you think learning about money is boring, chances are you aren't doing it. The National Foundation for Credit Counseling study found that only 59% of Americans grade themselves "A" or "B" on their personal finance knowledge, and 75% of adults still agree that they could benefit from professional advice for everyday issues.

Knowing what we know about how little people are appropriately prepared for retirement, how few people keep effective budgets, and how many people live paycheck to paycheck, there's always room for improvement.

How to improve: The information is out there — it's up to you to seek it out. Pick up a book, read an article, or listen to a podcast to improve your handling of money. (You don't have to stop at one.)